Applicants prior U.S. Pat. No. 6,508,208 issued Jan. 31, 2003, to Frasure, et al. discloses a water heater, for which the present invention provides improvements.
Reames, Jr., U.S. Pat. No. 4,175,518 dated 27, Nov. 1979, discloses a preheating device for hot water heaters, which employs hot gases of combustion from the flue to preheat incoming cold water and to continually preheat water stored in the water tank by natural recirculation. Use of the device provides for increased fuel efficiency because hot combustion gases from the heat source are used for warming of water before venting to the atmosphere, the result being an average increased temperature within the tank so that lesser amounts of fuel are required to reach any desired hot water temperature.
Leiter Klaus and Walder Gerhar, PCT Publication No. WO0113045 dated 22, Feb. 2001, discloses a sanitation unit having a hot water boiler and a water treatment unit with a functional element, in particular for the prevention of deposits of scale, whereby a circulation pump is provided, through which water taken from the hot water connection of the boiler can be routed through the functional element to the water treatment unit of the cold water connection of the boiler. The circulation pump and the functional element are constructed as one compact structural unit.
Burwell, U.S. Pat. No. 2,549,755 dated 24, Apr. 1951, discloses a burner base for a hot water tank of the type having a side arm heat-transfer coil carried within a chamber disposed adjacent the tank and means defining a flue passage in said base and communicating, respectively with the said open chamber and the chamber in which the heat-transfer coil of the said tank is carried, whereby gaseous products of combustion emanating from said burner may be directed from the bottom of said tank to the heat transfer coil thereof.
All the water heaters utilizing a coil that were found in the prior art relied on natural convection to circulate water through the coil. As a result, the coil can become overheated and get damaged when the burner is operating. None of the aforesaid prior arts teaches for increasing the efficiency by controlling the condensation problem. The condensation problem is solved by keeping the water vapor produced by the flame away from the cooler flue wall and by utilizing the hot air many a times by circulation of the same keeping safety and atomization of the system in mind. Moreover none of the prior arts also teaches a self-cleaning mechanism of tank and the coils used by the system. Hence, the prior art devices do-not appear to substantially use the waste heat energy and prevent the accumulation of the sediments, despite claims to the contrary.